Abstract: In order to solve the problems of difficulty and low efficiency in selecting water resources allocation scheme,a multi-attribute decision-making method of water resources allocation scheme based on Pythagorean fuzzy set with interval value and PROMETHEE algorithm is proposed in this paper. Firstly,the interval fuzzy decision matrix of decision-makers is constructed,and the weights of decision-makers and attributes are determined by the distance of relative proximity coefficient method,entropy method and Pythagorean fuzzy number. Secondly,the comprehensive weight and IVPFWA operator are used to aggregate the decision matrix of each decision-maker into the comprehensive matrix,and then the final ranking results of water resources allocation schemes are obtained by PROMETHEE method. Finally,the algorithm used in this paper to select the optimal water resources allocation plan in City S as a case,and through comparison with the results of other methods,it finally shows that the method in this paper can accurately determine a reasonable water resources allocation plan,and the method is effective and reliable.